Aerial images published by The West Australian showed a trail of twisted wreckage, with some wagons covered by their loads of iron ore.

The driver of the 268-car train had stopped around 80 kilometres earlier to inspect one of the wagons.

More than 130 workers have been deployed to fix the track and recover the wreckage, with BHP saying it would be removed "over the next few days".

The train travelled for 90 km by itself before being derailed near Turner, approximately 120km south of Port Hedland, leaving about 1.5km of track damaged.

However, it said, operations would be maintained and the use of reserves would mean there would be no interruption to supply.

Despite the closure of its rail network, BHP's iron ore mines remain open and operating.

In July rival mining giant Rio Tinto clocked up a world first when its maiden driverless train voyage carried 28,000 tonnes of iron ore 280 kilometres from its Mount Tom Price mine to a WA port.

"We will be liaising with our customers in relation to our contractual commitments over this period", she added.

The Australian Transport Safety Bureau said damage to the train was substantial and it is estimated about 1.5km of track was damaged. There was no indication of what had caused the train to move without its driver.

BHP has suspended its train operations.

Nineteen people were killed and a wave of toxic waste was unleashed when a dam burst at the mine in one of Brazil's worst environmental disasters.